Pushbutton actuated switch with fluidic means creating a bernoulli effect and resulting in momentary action

ABSTRACT

A fluidic switch having a pair of separately pivotable spring separated arms each having a flat plate secured thereto. The arms are moved to a substantially parallel position, by a pushbutton, so that fluid introduced centrally through one of the plates creates a fluid flow attraction between the plates sufficient to overcome the spring load. A second spring moves the arms in unison, when the force on the pushbutton is released, until an electric contact on one arm is abutting a stationary electrical contact at which time both springs oppose and overcome the fluidic attraction thereby separating the plates and opening the electrical contacts.

l37/(Inquired); 25 l/(Inquired); 200/81 0 United States Patent 1111 3,573,413

[72] Inventor Nathaniel B. Kell [56] References Cited Indianapolis, UNlTED STATES PATENTS 9: 2 x2 1969 2,722,579 11/1955 Rohacs 200/160X Patented Apr. 6,1971 587,260 7/1897 Houghtoru. 200/160 [7 3] Assignee General Motors Corporation Prir'nary Examiner-Robert K. Schaefer Detroit, Mich. Assistant ExaminerRobert A. Vanderhye Attorneys-W. E. Finken, A. M. l-leiter and D. F. Scherer PUSHBUTTON ACTUATED SWITCH WITH A BsTRACT. A flu1d1c switch havmg a pair of separately pivotable sprmg separated arms each havlng a flat plate FLUID: MEANS CREATING A BERNOULLI secured thereto The arms are moved to a substantially aral- EFFECT AND RESULTING IN MOMENTARY p lel posltlon, by a pushbutton, so that flmd introduced centrally ACTIPN through one of the plates creates a fluid flow attraction 4 Clams 2 Drawing Figs between the plates sufficient to overcome the spring load. A [52] US. Cl 200/160, second spring moves the arms in unison, when the force on the pushbutton is released, until an electric contact on one arm is [51] lnt.Cl ..H0lh 13/50 abutting a stationary electrical contact at which time both [50] Field of Search 200/ 160;- springs oppose and overcome the fluidic attraction thereby separating the plates and opening the electrical contacts.

PUSHBUI'ION ACTUATED SWITCH WITH FLUIDIC MEANS CREATING A BERNOULLI EFFECT AND RESULTING IN MOMENTARY ACTION This invention relates to switches and more particularly to momentary contact switches.

Many electric circuits require a momentary contact switch to energize or deenergize a portion or all of the circuit. The present invention provides such a switch by utilizing a fluid attraction force or the Bernoulli Effect" and a return spring to close the switch, at the will of the operator, and the return spring plus a separating spring to open the switch automatically. One such electric circuit is shown in US. Pat. No. 3,316,533.

The switch, which is the subject of the present invention, is comprised of a pair of pivotally mounted arms which are urged to separation against stops in a switch housing by a compression spring located between the two arms. One of the arms is also acted on by a second compression return spring which is located between that ann and a portion of the switch housing. Each of the arms has a flat plate member secured thereto and one of these flat plate members has an opening which is adapted to receive a fluid from a fluid source.

When the arms are separated, by the separating spring, the fluid is freely exhausted through the opening to atmosphere. However, when an operator force on the one arm moves the two plates into a close parallel relationship, the fluid flow is then forced to flow in the confined space between the plates. The fluid flow in this confined space results in an increase in fluid velocity which is, of course, accompanied by a reduction in fluid pressure. Thus the reduction in fluid pressure between the plates permits atmospheric pressure operating on the opposite side of the plates to hold the two in the parallel relationship thus established. This attractive force, created by the pressure differential, is sufficient to overcome the separating spring force between the arms and thus maintain the parallel relationship between the plates. However, when the input force movement is removed, the return spring, operating between one arm an the housing, will move both of the arms in unison maintaining the parallel relationship between the plates until an electrical contact on one of the arms engages a stationary contact on the switch frame. When this contact is made, the return spring on the one arm, then acts as a separating spring since the arm with the electrical contact is substantially fixed to the switch frame relative to return spring. Thus the return spring and the separating spring will act together to separate the arms. This combined spring force will be sufficient to overcome the attractive force between the plates thus causing the arms to separate with the return spring moving the one arm up against the stop 48 and the separating spring urging the other arm back against the stop 46 and opening the electrical contact. Thus it is seen that the switch makes the momentary electrical contact then immediately disconnects this contact.

It is therefore an object of this invention to provide in an improved switch a pair of arms having flat plates thereon, a passage for introducing fluid between the plates thereby creating an attractive force, and a spring to move the arms to close the switch and to separate the arms after the switch is closed.

Another object of this invention is to provide in a switch a pair of spring separated arms, a pushbutton to move the arms into a parallel relationship, a fluid passage which directs fluid between the arms to create an attractive force to overcome the separating spring, and a return spring to move both arms until the switch is closed and then assisting the separating spring to overcome the attractive force to open the switch and return the arms to their rest positions.

These and other objects and advantages will be more apparent from the following description and drawing of the preferred embodiment in which:

FIG. 1 is an elevational view of the switch; and

FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1.

Referring to the drawings wherein like characteristics represent like or corresponding parts, there is shown a frame member 10 enclosing a switching device generally designated 12. The switching device 12 has a pair of flat sheet metal arms 14 and 16 which are pivotally mounted on a pivot pin 18 which is secured to the frame 10. The arml4 has a flat plate 20 secured to one end and an electrical contact 22 secured thereto and insulated therefrom by an insulating material 24 which may be made of plastic or any other commonly used insulating material. The electrical contact 22 is connected to an electrical wire 26 which is directed through an opening 28 in the frame 10 and is adapted to be connected into an electrical circuit. The other arm 16 also has a flat plate 30 secured thereto. The plate 30 has an opening 32 which is aligned with an opening 34 in a plug 36 which is connected to a flexible tubing 38. The flexible tubing 38 is adapted to direct air, or other fluid, from a fluid source, not shown, through the opening 32 between the plates 20 and 30.

The anns 14 and 16 each have a spring seat 40 and 42 respectively for locating a separating spring 44 between the two arms. The spring 44 supplies the force to the arms 14 and 16 to separate the arms and to urge them against stops 46 and 48 respectively. The arm 16 has another spring seat 50 which locates a return spring 52 which is held in compression between the arm 16 and a spring seat 54 on the frame 10. A return spring 52 also urges the arm 16 against the stop 48.

The frame member 10 has secured thereto an electrical contact 56 which has a member 58 aligned with the electrical contact 22. The electrical contact 56 is insulated from the frame 10 by a conventional insulating material 60 and is connected to an electric lead 62 which passes through the opening 28 and is adapted to be connected into an electrical circuit. Also located in the frame 10 is a bushing 64 which guides a pushbutton or switch input member 66. The one end of the pushbutton 66 abuts the arm 16 so that movement in the direction of arrow A of the pushbutton will cause the arm 16 to pivot about the pin 18 until the face of plate 30 is parallel to the face of plate 20.

When the plates 20 and 30 are in a close parallel relationship and a fluid, such as air, is flowing through the flexible tubing 38 and out the opening 32, an attractive force between the plates 20 and 30 will be created by the increased velocity of the flowing fluids between the plates and the reduction of pressure caused by this increased velocity. The attractive force created by this phenomena which is quite often termed the Bernoulli Effect is sufficient to overcome the force in the separating spring 44 and thus maintain the plates 20 and 30 in their parallel relationship as long as the pushbutton 66 is held inward in the direction of arrow A. Also in this position, the electrical contact 22 will remain separated from the electrical contact 56 until the pushbutton 66 is released. When the pushbutton 66 is released, the return spring 52, acting on the arm 16, will cause the arm 16 to begin to pivot back toward stop 48. The attraction force, still being sufficient to overcome the spring 44 will cause the arm 14 to follow along with the arm 16 until the electrical contact 22 engages the contact 56.

When the electrical contact 22 engages the electrical contact 56, the arm 14 is restrained from further movement so that the force of the separating spring 44 and the force of the return spring 52 both act as separating springs thereby causing the arm 16 to move away from the arm 14, breaking the attraction force between the plates 20 and 30 and returning the switch 12 to the neutral position shown.

The invention is not intended to be limited to the above description and drawings since obvious modification and variations will be readily apparent to those skilled in the art.

lclaim:

1. In a switching device a housing pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm; a second pivot arm pivotable mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; spring means for urging the second arm against said housing; and switch input means for pivoting said second aim against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released.

2. In a switching device a housing; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm and the first electrical contact secured thereto intermediate said pivot means and said flat plate; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; spring means for urging the second arm against said housing; a second electrical contact secured to said housing and aligned with said first electrical contact; and switch input means for pivoting said second arm against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released, and said arms being separated by the spring force when the first and second electrical contacts are in an abutting relationship.

3. In a switching device a housing; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; first spring means for urging the second arm against said housing; second spring means located between said arms for separating said arms; and switch input means for pivoting said second arm against the force of both of said spring means to place the plates on said first and second anns into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates greater than said second spring means separating force to maintain said plates in parallel relationship so that said first spring means will move both pivot arms in unison when said switch input means is released.

4. In a switching device a housing having a pair of stop means thereon; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm and a first electrical contact secured thereto intermediate said pivot means and said flat plate; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conduct ing means for conducting fluid to and through said flat plate on said second pivot arm; first spring means for urging the second arm against said housing; second spring means disposed between said arms for applying a separating force thereto; a second electrical contact secured to said housing and aligned with said first electrical contact; and switch input means for pivoting said second arm against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released, and said arms being separated by the force of both spring means when the first and second electrical contacts are in an abutting relationship whereby both spring means will move said second arm against one stop means, said second spring means will move said first arm against said other stop means, and said electrical contacts will be separated. 

1. In a switching device a housing ; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm; a second pivot arm pivotable mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; spring means for urging the second arm against said housing; and switch input means for pivoting said second arm against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released.
 2. In a switching device a housing; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm and the first electrical contact secured thereto intermediate said pivot means and said flat plate; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; spring means for urging the second arm against said housing; a second electrical contact secured to said housing and aligned with said first electrical contact; and switch input means for pivoting said second arm against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released, and said arms being separated by the spring force when the first and second electrical contacts are in an abutting relationship.
 3. In a switching device a housing; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; first spring means for urging the second arm against said housing; second spring means located between said arms for separating said arms; and switch input means for pivoting said second arm against the force of both of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conduCting means will create an attractive force between said plates greater than said second spring means separating force to maintain said plates in parallel relationship so that said first spring means will move both pivot arms in unison when said switch input means is released.
 4. In a switching device a housing having a pair of stop means thereon; pivot means secured to said housing; a first pivot arm pivotably mounted on said pivot means having a flat plate secured to one end of the arm and a first electrical contact secured thereto intermediate said pivot means and said flat plate; a second pivot arm pivotably mounted on said pivot means and having a flat plate secured thereto; fluid conducting means for conducting fluid to and through said flat plate on said second pivot arm; first spring means for urging the second arm against said housing; second spring means disposed between said arms for applying a separating force thereto; a second electrical contact secured to said housing and aligned with said first electrical contact; and switch input means for pivoting said second arm against the force of said spring means to place the plates on said first and second arms into parallel relationship whereby fluid introduced to said fluid conducting means will create an attractive force between said plates to maintain said plates in a parallel relationship so that said spring means will move both pivot arms in unison when said switch input means is released, and said arms being separated by the force of both spring means when the first and second electrical contacts are in an abutting relationship whereby both spring means will move said second arm against one stop means, said second spring means will move said first arm against said other stop means, and said electrical contacts will be separated. 